*{
  margin: 0;
  padding: 0;
}
body{
  height: 700px;
  border:1px solid #ff0099;
  color: #000;
  font: 28px 微软雅黑, 黑体, Arial, "Times New Roman", sans-serif;
  text-align: center;
  /*filter: alpha(opacity:40);
  opacity: 0.4;*/
}
header,aside,main,footer{
  margin:10px;
  padding: 10px;
}
header{
  height:10%;
  background-color: red;
}
header nav{
  background-color: rgb(54, 150, 121);
}
aside{
  float: left;
  background-color: yellow;
  height: 65%;
  width: 250px;
  margin-top: 0;
}
main{
  margin-left: 300px;
  background-color: blue;
  height: 65%;
}
footer{
  background-color: green;
  height:10%;
  clear: both;
}
